>Is any way in VFP6.0 to link any API library to access on TCP/IP and transfer files. I need transfer the data with Modem on peer to peer computers with TCP/IP protocol connected only to telephone line.
>I need use the Microsoft TCP/IP Protocol. Please help me. Thank You very much.

What about using FTP? This can be done with the command line FTP built into windows or with something like wwipstuff from www.west-wind.com